In aviation it is of course well known, that most aircraft movement on the ground as well as in the air is controlled, directed or just anounced by means of radio communication. This requires that in an airport an operator for the radio should be on active duty whenever an aircraft needs landing, take off or taxi information or instruction. It is equally well known, that one of the most important information needed by the pilot is wind direction and runway traffic direction to perform safe landings and take offs. There are many instances, when this radio information is unavailable to the pilot for various reasons; radio may be unattended since operator busy otherwise, radio may be out of order, pilot may have tuned wrong channel or volume turned down, or radio station may be closed during nighthours. Runway approach indicator lights "RAIL's" as used on a few airports, are turned off during nighthours except on a few very large airports with 24 hours operation. RAIL's are manually controlled and become useless once the operator goes home. Most general aviation airports do not own enough real property next to the runways and therefore could not use the RAIL's, besides the enormous cost.
It is exactly in those circumstances that a pilot needs help, when he flies into an airport, radio unattended, runway not exceptionally long where even a little tailwind can endanger the safety of the occupants of the craft and create a dangerous situation. Airport accident statistics show, that most accidents occur on or near airports and many of those accidents are a direct result of a wrong decision made by the pilot. According to federal aviation regulation FAR 91.3(a), the pilot in command of an aircraft is directly responsible for, and is the final authority as to the operation of that aircraft. Due to this fact it is possible that under certain circumstances with unavailable runway traffic direction information and, for example exactly 90.degree. cross-wind or absolute calm, two pilots can legally make two opposing decisions as to which way to land or to take off. This has caused many accidents. Windsocks and windtees do not solve this problem, since they do show the direction of the wind but not necessarely the direction of the runway which should be used. It must be pointed out, that in aviation one runway is normally used from both directions, so the approaching or departing aviator must make a decision as to which way he should use that runway.
The automatic runway traffic direction control, the "ARTRAC" for short, solves this problem well as a prototype installation on a general aviation airport proves out and does it economically.